Method of preparing liquid fuel for burning



Aug. 25, 1931. J. l. MCMULLEN '1,820,755

I METHOD OF PREPARNG LIQUID FUEL FOR BURNING Filed March 9, 1929dttozmql Patented Aug. 25, 1931-V UNITED STATES JOSEPH I. MCMULLEN, orVBETHESDA, MARYLAND METHOD OF PBEPARING LIQUID FUEL FOR BURNINGApplication mea Maren 9, 1929. serial No. 345,825.

(GRANTED UNDER THE ACT F MARCH 3, 1883, AS AMENDED APRIL 30, 1928; 3700. G. 757) This application is filed under the provisions of the act ofMar.'3, 1883, c. 143, U. S. Statutes XXII, p. 625, as amended by act ofApr. 30, 1928. The inventiony described herein may be manfactured andused by or for the Government .for Government purposes, Without thepayment to me of any royalty thereon.

This invention relates to liquid fuel burners and has for its `generalobject an improved method for securing complete combustion ofandmaxi-mum heating efficiency from the fuel. l

Another object of this invention is to prjovide a liquid fuel burnerhaving facilities for centrifugally raising. vfuel from a reservoir anddischarging it; atomized and suitably mixed With air, into a combustionchamber in the form of a whirling frusto-conical shell. l

Anot er object of this invention is to provide a fuel burner in whichthe fuel is atom-l y ized as'it travels'from the reservoir to thedischarge orifice andatthe same ,time subjected to the action of air andsteam, the mixture being expanded in the course of its travel from thesource of supply to the discharge.

Another object of this invention is to provide aburner in which the fuelis centrifugally 4rasied from the reservoir to the zdis charge orifice,and is subjected at approxi.

mately the initial point of its travel to the combined action of air andsteam' so that before being discharged into the combustion chamberalsufiicient time interval will have elapsed to permit interactionbetween the oil, steam and air to secure a completely combustiblemixture. l

Other objects of this invention are to prod uce a burner which iseconomical in fuel consumption, readily removable from the furnace tofacilitate repairs, simple in construction and inexpensive tomanufacture, and one which owing to the manner of discharging the fuelinto the combustion chamber affprds a concentrated heating effect.

In order to make my invention more clearly understood, I have shown inthe accom- 50 panying drawings means for carrying the same intopractical effect, without limiting the improvements in their usefulapplica- 'tions to the particular constructions, which nular dischargeorifice, while the lower end 5 of the mixing chamber is formed with afuel. reservoir in communication with a suitable source of supply., aninverted frusto-conicalshaped atomizing head rotatablyA mounted in themixing chamber, the upper lend of the head being disposed immediatelybeneath the spreader, the lower end projecting into the ,fuel in thereservoir, a series of spirally arrangedI divergently associatedatomizing blades carried by the head, the -depth of the bladesdecreasing gradually from the upper to the vlower end of the head, anannular series of chambers communicating with the mixing chamber atapoint adjacent the fuel reservoir and means for introducing andintermingling air and steam within the chambers.

In the drawings forming a part of this specification: v n

Figure 1 is a view partly 1n elevation and partly in section of anapparatus capable of carrying out my invention.

Figure 2 is a top view taken on line 2-2 of Figure 1.

Figure 3 is a fragmentary sectional vlew of the rotor showing themounting of the fins. In the prevailing types of fuel burners especiallythose mixing oil and steam, one of the principal defects resides in thefailure on the part of the designers to allow a sufiicient l timeintervalto elapse after the steam, oil and.` air have been 1nterm1nglcdto secure a completely combustible mixture, and 1t 1s therefore the aimand purpose of this invention to avoid this defect by providing anapparatus wherein as the oil starts toward the discharge orifice, it istreated with air and steam which mixture is thoroughly inter-` ICO minled prior to its discharge into the combustion chamber.

Referring more particularly by numerals vto the drawings in which thesame elements are designated by like symbols of reference throughout and'especially to Figure 1, the apparatus comprises .a base, preferablycast in a single piece of some suitable metal, so as t0 form a singlecomposite structure.

The base is provided with a circular bottom flange 1, adapted to rest ona support such as the floor of the furnace, althoug it is apparent thatit may be of any other desired configuration, havlng formed integrallytherewith, upwardly extending inwardly sloping walls 2. The walls 2 areprovided with a series of apertures 3 designed to admit air to acircular casing 4, forming an up-' projecting extension ofthe slopingwalls 8 of increased diameter extending upwardly from the top of thecasing and terminatingI in an outwardly extendmg Bange 9. The recessformed by the walls 8 is intended toaccommodate an air inductionmechanism mounted on a drive shaft 11 projecting from the motor. The airinduction mechanism consists of a fan having angularly disposed blades12 intended to draw air upward throu h` the a rtures 3 and 4thus amongother 'o jects whlch willsubsequentl be more fully understood, providefor coo `ingthe motor.

A mixing chamber,.preferably cast in a single' piece and of the samematerial -as the base, is mounted on the frame above the motor. Theymixing chamber comprises a fiat circular base 13 mounted on the flange9 of the frame and held in place by bolts 14.

The base 13 is formed 'with' a central depressed portion 15 forming awell, which portion is provided in addition with a recess 16 having acentral a erture containing a packing (gland `17 in tie bottom,.throughwhich the rive shaft 11 extends. r

A ball race 18 is mounted'on that portion of the shaft within the recessformed by the wall 16, and a ball race 19 is positioned therein, adaptedto form a bearing by providing ball bearin s 21 operatingin the same. Inaddition a eeper 22 is fixed in the top of the recess flush with thebottom of the depressed portion 15 and held therein by a screw 23.

l An upper casing is formed with walls 24 extending upwardly from thebase 13, having angular extensions 25 projecting inwardly and joinedwith outwardly projecting sides 26 forming a truncated conlcal recesswith the tapered walls 15 of the central depression in the base. Theside 26 is provided at its top with an annular shoulder 27, adapted tosupport rebrick 28 or other material forming the bottom of thecombustion chamber of the furnace with whichthe apparatus is associated.y I

An atomizing head in the nature of a rotor 29 having tapered blades 31positioned spirally on the outer face, is mounted on that portion of theshaft extending into the mixing chamber and fixed thereon by a spline 32or held in any other suitable manner. vThe rotor 29 is preferably castin the form'of a truncated conical body of some light metal with theblades integral therewith and it may be hollow in form as shown inFigure 2, including an extension 32, to lend to the lightness thereof.

The rotor 29 acts as a mixingl member. for' the material introduced intothe chamber formed b the to casing and is rotated at a very rapid rateveing 'carried on the drive shaft of the motor. The shaft 11 extendsabove the top of the rotor and a dish shaped spreader 33 is mounted onthe end, the top thereof bein iush with the .bottom of the combustion camber in the furnace, and the sides tapered.

It will be noticed that the portionv 26 of the side 26 adjacent thesides of the spreader, is sloped outwardly from the major portion of theside 26 and corresponds in configuration with the tapered sides 33 ofthe spreader sothat the material thrown out by the revolving rotor willbe sprayed out in the form of a truncated conical shell.

The exterior surface of the atomizing head and the confronting surfaceof the mixing chamber difer in slope to compensate for the configurationof the 'atomizing blades (31) whic graduallyl decrease in depth from theupper to the lower end of the head, the construction of the blades inconjunction with the adjacent surface of the mixing chamber formin'channels gradually increasing in depthA rom the lower to the upper endofthe atomizing head to permit expansion of the mixture of steam, air andoil as it travels from the fuel reservoir to the discharge orifice.

Oil is introduced into the mixing chamber through a line 34 having aninlet in the .bot-

tom of the depressed portion 15 formed in they bast 13, so that thestream will act to produce a body of oil in the well formed by thedepression 15.

The base is provided with a series of apertures 35 communicating withthe apertures 3 in the bottom of the frame so that air drawn up throughthe motor by rotation of the fan blades 12 will force the same into themixing chamber through the several apertures. `A series of nipples 36havin their free end inclined as at 36 are fitted into the apertures. Byreason of the inclined 'ends with the highest portion faced towardtherotor, any material splashed will not fall through the apertures. A fIn this connection it is to be noted the supply of fuel to the oilreservoir is suitably regulated so that the fuel therein will not exceeda level which would interfere with the return to the reservoir of oildischarged into the chambers (47') communicating with the lower end ofthe atomizing head.

The base 13 is provided in addition with an aperture 37 'adapted toreceive a nipple (38)l having its upper end (38')7 inclined in a similarmanner to the nipples 36 and for the same purpose.A The nipple 38 isconnected with a suitable source of steam. There is shown an apparatus.consisting of a plurality of check valves 41 and 42 and a casing 43forming an enlarged chamber, interposed in the line, said chamber havingtherein electrodes (44). l

The electrodes'44 are in electric connection with a cable 46 containinga plurality of conductors, which enter the lower part of the chamber.When water underthe usual pressure is introduced into the line, itpasses through the valve 41 and the casing 43 and in contact with theelectrodes, the temperature is immediately raised, and it is convertedinto steam almost instantaneously, and by reason of the pressure exertedit passes through the valve 42 through a pipe 39 and out the nipple 38into the mixing chamber.. It is apparent that if too high a pressure isgenerated in the casing the valve 41 will be automatically closed andthe pressure relieved by the steam passing through the valve 42 untilthe pressure is sufficiently lowered to allow opening of the valve 4l bythe water head.

The operation of the apparatus will be readily undetstood. Oil isintroduced through the line 34 and allowed to collect as a body in thewell formed in the bottom of the mixing chamber where it is drawn olf bythe rotating [blades of the rotor into the enlarged mixing chamberformed by the walls 24, where now in'atomized form it is mixed withsteam comin through the line 38 and air, forced throng the apertures 35by action of the fan blades 12. These materials are further atomizedandcommingled while being conducted along the body of the rotor, which,having an extended Contact surface,

imparts a shapeto the material so that when 4it is discharged past thetapered edges of the spreader 33, it assumes the 'form of a truncatedconical shell which has a large surface area for-burning.

` The enlarged portion' of the mixing chamber adjacent the lower end ofthe atomizing head is sub-divided by partitions (47) into an annularseries of compartments (47 The space between th'e'rotor and the side 26also serves as an additional mixing chamber as well as to impart thedesired form to the fuel.

It has been found that certain qualities are jecting the atomized oil tothe combined action of steam and air at approximately the starting pointof its travel from the reservoir to the discharge orifice and furtherdisintegrating and at the same time expanding the mixture to thedischarge, secure complete fuel combustion and thus eliminates all sootaccumulation. 4

While I have shown and described the preferred embodiment of myinvention, I wish it to be understood that I do not confine myself tothe precise details herein set forth, as it is apparent that many changeand variations may be lmade therein, by those skilled in the art,without departing from the spirit of the invention, or exceeding thescope of the appended claims.

I claim:

1. A method of burning li uid fuel comprising, collecting a body of ueland maintaining a constant level thereof, drawing fuel from the surfacethereof, mixing the fuel with steam and air, said air beingI suppliedunder forced draft, drawing the combustiblel mixture upwardly in theform of a rotating inverted truncated cone, and ejecting the fuel forburning.

2. A method of burning li uid fuel comprising, collecting a body of ueland maintaining aconstant level thereof, drawing fuel from the surfacethereof into a mixing cham- -ber for atomizing same, mixing the-fuelwith steam and air, said air being supplied under forced draft upwardly,drawing .the 'com bustible mixture upwardly in the form of a rotatinginverted truncated cone and further atomizing same, and ejecting Vthefuel for burning.

3. A method of burning liquid fuel" comprising, collecting a bodv offuel, and maintaining a constant level thereof, drawing fuel from thesurface thereof into a mixing chamber for atomizing same, mixing thefuel with steam and air, said air being supplied under forced draftupwardly, drawing the combustible mixture upwardly in the form of arotating inverted truncated cone and further atomizing same, andejecting the fuel for. burning to present a horizontal ring ignltlonsurface.

4. A method of burning li uid fuel comprising, collecting a body of ucland mamtaining a constant level thereof, drawing fuel from the surfgcethereof into a mixing chamber for atomizing same, mixing the fuel withsteam and air, said air being supplied under 5 forced draft upwardly,drawing the com,-

bustible mixture upwardly in the form of a rotating inverted truncatedcone and discharging the mixture in the form of a, thin angular ring,for further atomizing the mix- 1o tu-re and ejecting the fuel forburning to present a horizontal ring ignition surface.

In testimony whereof I affix my signature.

` JOSEPH I. MCMULLEN.

